Power feeding device and power feeding method

ABSTRACT

A power feeding device includes a power feeder that wirelessly feeds power to one of a plurality of power receivers, a transceiver that communicates with the plurality of power receivers, and a controller that causes, when the transceiver receives a plurality of signals from two or more of the plurality of power receivers, the power feeder to suspend the feeding of power to the one of the plurality of power receivers for a predetermined period.

BACKGROUND OF THE INVENTION Technical Field

The present invention relates to a power feeding device and a powerfeeding method that wirelessly feeds power to a power receiving device.

Related Art

A wireless power feeding system is known that wirelessly (withoutcontacting) feeds power from a power feeding device to a power receivingdevice (for example, see patent literature 1). This wireless powerfeeding system feeds power from the power feeding device to the powerreceiving device by generating induced electromotive force to asecondary coil owned by the power receiving device, due to a flux changegenerated in a first coil owned by the power feeding device.

Furthermore, in the wireless power feeding system described above,wireless communication is carried out between the power feeding deviceand the power receiving device by, for example, Bluetooth (registeredtrademark). The power feeding device controls the feeding of power tothe power receiving device based on power receiving information obtainedvia wireless communication from the power receiving device.

Patent Literature

[Patent Literature 1] Japanese Unexamined Patent Application PublicationNo. 2015-39271

SUMMARY

In the conventional power feeding device described above, for example,in a state having two power feeding devices arranged in a line, a powerreceiving device may be installed at almost the same time to each of thetwo power feeding devices. At this time, because the wirelesscommunication distance is generally longer than the wireless powerfeeding distance, a phenomenon may occur wherein each power feedingdevice obtains power receiving information from a power receiving devicethat is different from the power receiving device that is its pair (aso-called cross connection). As a result, each power feeding devicecannot reliably feed power to the power receiving device, which is itspair.

One or more embodiments of the present invention provides a powerfeeding device and a power feeding method that can reliably feed powerto a power receiving device.

The power feeding device according to one or more embodiments of thepresent invention is provided with a power feeding unit that wirelesslyfeeds power to a power receiving device, a communication unit thatcarries out communication between the power receiving device, and acontrol unit that controls both the power feeding unit and thecommunication unit, wherein the control unit stops the feeding of powerto the power feeding unit for a predetermined period and restarts thefeeding of power to the power feeding unit based on the communicationunit receiving a signal from the power receiving device.

According to one or more embodiments of the invention, the control unitstops and restarts the feeding of power to the power receiving devicewhen the communication unit receives a signal from the power receivingdevice to which power is to be fed and a signal from another powerreceiving device to which power is not to be fed. By this, thecommunication unit only receives a signal from the power receivingdevice to which power is to be fed by stopping the feeding of power tothe other power receiving device when the feeding of power to the powerreceiving device is restarted. As a result, the power feeding device canreliably receive power receiving information from the power receivingdevice to which power is to be fed, and can reliably carry out feedingof power to the power receiving device based on this power receivinginformation.

For example, in the power feeding device according to one or moreembodiments of the present invention, the control unit may be configuredto set a time period specific to the power feeding device as thepredetermined period.

According to one or more embodiments of the invention, because thepredetermined period is a period specific to the power feeding device,the period for stopping the feeding of power can be made to be differentby each of the plurality of the power feeding devices when a pluralityof the power feeding device is arranged in a line. As a result, thetiming for restarting the feeding of power to the power receiving devicecan be made different in each of the plurality of the power feedingdevice.

For example, in the power feeding device according to one or moreembodiments of the present invention, the control unit may be configuredto set the predetermined period based on a random number specific to thepower feeding device.

According to one or more embodiments of the invention, the predeterminedperiod can be set using a simple method.

For example, in the power feeding device according to one or moreembodiments of the present invention, the control unit may be configuredto generate the random number based on an address assigned to the powerfeeding device.

According to one or more embodiments of the invention, the predeterminedperiod can be set using a simple method.

For example, in the power feeding device according to one or moreembodiments of the present invention, the signal may be configured toinclude at least one of an address, an ID, or a received signal strengthindicator.

According to one or more embodiments of the invention, the feeding ofpower to the power feeding unit can be stopped for a predeterminedperiod based on at least one of an address, an ID, or a received signalstrength indicator.

For example, in the power feeding device according to one or moreembodiments of the present invention, the control unit may be configuredto control the power feeding unit based on the signal after restarting.

According to one or more embodiments of the invention, the power feedingunit can be reliably controlled based on a signal after restarting.

For example, in the power feeding device according to one or moreembodiments of the present invention, it can be configured so that thepower feeding unit wirelessly feeds power to each of the plurality ofthe power receiving device, and the control unit repeats the stoppingand restarting of power feeding to the power feeding unit a plurality oftimes based on the communication unit receiving the signal from each ofthe plurality of the power receiving device, and determines that theplurality of the power receiving device is installed on the powerfeeding device based on the communication unit receiving the sameplurality of signals.

According to one or more embodiments of the invention, it can be easilydetermined that all of the plurality of the power receiving device areinstalled on the power receiving device when the communication unitreceives the plurality of signals from each of the plurality of thepower receiving device.

For example, in the power feeding device according to one or moreembodiments of the present invention, the control unit may be configuredto set power feeding conditions for the power feeding unit to feed powerto each of the plurality of the power receiving device based on theplurality of signals from the plurality of the power receiving devicereceived by the communication unit.

According to one or more embodiments of the invention, power can bereliably fed to each of the plurality of a power receiving device basedon power feeding conditions.

For example, in the power feeding device according to one or moreembodiments of the present invention, the communication unit may befurther configured to communicate with a management device that managesthe power feeding device, and the predetermined period may be notifiedto the communication unit from the management unit.

According to one or more embodiments of the invention, the control unitcan stop the feeding of power to the power receiving device based on thepredetermined period notified from the management device.

Furthermore, a power feeding method according to one or more embodimentsof the present invention includes a step for wirelessly feeding power toa power receiving device, a step for carrying out communication betweenthe power receiving device, and a step for stopping the feeding of powerto the power receiving device for a predetermined period and restartingthe feeding of power to the power receiving device based on receiving asignal from a plurality of the power receiving device.

According to one or more embodiments of the invention, the feeding ofpower to the power receiving device stops and restarts when a signalfrom the power receiving device to which power is to be fed and a signalfrom another power receiving device to which power is not to be fed arereceived. By this, only the signal from the power receiving device towhich power is to be fed it is received by stopping the feeding of powerto the other power receiving device when the feeding of power to thepower receiving device is restarted. As a result, the power feedingdevice can reliably receive power receiving information from the powerreceiving device to which power is to be fed, and the feeding of powerto the power receiving device can be reliably carried out based on thispower receiving information.

One or more embodiments of the present invention can be realized notonly as a power feeding device provided with these characteristicprocessing units, but can also be realized as a control method that hasthe processes executed by these characteristic processing units includedin the power feeding device as its steps. Moreover, it can also be arealized as a program that makes a computer function as a characteristicprocessing unit included in the power feeding device, or a program thatexecutes the characteristic steps included in the control method in acomputer. It goes without saying that this kind of program can bedistributed via a non-temporary recording medium that can be read by acomputer such as a CD-ROM (Compact Disc-Read Only Memory), or acommunications network such as the internet.

According to the power feeding device and the power feeding method inone or more embodiments of the present invention, power can be reliablyfed to a power receiving device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating the functional configuration ofthe wireless power feeding system according to one or more embodimentsof the present invention.

FIG. 2 is a flow chart illustrating the flow of operations of the powerfeeding device according to one or more embodiments of the presentinvention.

FIG. 3 is a time chart illustrating a short beacon and a long beacontransmitted from the power feeding device according to one or moreembodiments of the present invention.

FIGS. 4A-4B are schematic diagrams for describing the operation of thepower feeding device according to one or more embodiments of the presentinvention.

FIG. 5 is a schematic diagram for describing the operation of the powerfeeding device according to one or more embodiments of the presentinvention.

FIG. 6 is a flow chart illustrating the flow of operations of the powerfeeding device according to one or more embodiments of the presentinvention.

FIG. 7 is a schematic diagram for describing the operation of the powerfeeding device according to one or more embodiments of the presentinvention.

FIG. 8 is a flow chart illustrating the flow of operations of the powerfeeding device according to one or more embodiments of the presentinvention.

DETAILED DESCRIPTION

Hereinafter, one or more embodiments of the present invention will bedescribed with reference to drawings. Note that the embodimentsdescribed below all illustrate inclusive or specific examples. Thevalues, shapes, materials, components, disposition location andconnection state of the components, and the like, are only examples, anddo not limit the present invention. Furthermore, components in theembodiments below that are not described in the claims are described asoptional components. Each drawing does not always strictly disclose eachdimension or each dimension ratio and the like.

1-1. Summary of Wireless Power Feeding System

First, a summary of a wireless power feeding system 2 according to oneor more embodiments of the present invention will be described referringto FIG. 1. FIG. 1 is a block diagram illustrating the functionalconfiguration of the wireless power feeding system 2 according to one ormore embodiments of the present invention.

The wireless power feeding system 2 is a system for wirelessly (withoutcontact) feeding power using, for example, an electromagnetic inductionmethod. As illustrated in FIG. 1, the wireless power feeding system 2 isprovided with a power feeding device 4 and a power receiving device 6(or a power receiver).

The power feeding device 4 is a device for wirelessly feeding power tothe power receiving device 6, and is, for example, a power feedingplatform or the like installed on a table.

The power receiving device 6 is a device for wirelessly receiving power,and is, for example, an electronic apparatus or the like such as asmartphone or digital camera. By the power receiving device 6 beinginstalled (mounted) on the power feeding device 4, power from the powerfeeding device 4 is wirelessly supplied to the power receiving device 6.

1-2. Configuration of Power Feeding Device

Next, the configuration of the power feeding device 4 according to oneor more embodiments of the present invention will be described referringto FIG. 1.

As illustrated in FIG. 1, the power feeding device 4 has a power sourceunit 8 (one example of a power feeding unit or power feeder), aresonance circuit 10, a power feeding coil 12, a wireless communicationunit 14 (one example of a communication unit or transceiver), and acontrol unit 16 (or a controller).

The power source unit 8 receives power from a commercial power source18, and supplies AC power of a prescribed frequency to the resonancecircuit 10.

The resonance circuit 10 resonates at a resonance frequency that issubstantially the same as the prescribed frequency of the AC powersupplied from the power source unit 8.

The power feeding coil 12 is a so-called primary coil that generates amagnetic field for wirelessly feeding power to the power receivingdevice 6, by AC power of a prescribed frequency being supplied from thepower source unit 8 via the resonance circuit 10.

The wireless communication unit 14 carries out wireless communicationwith the power receiving device 6 based on, for example, a Bluetooth(registered trademark) Low Energy (BLE) method. The wirelesscommunication unit 14 receives, for example, power feeding information(described later) or the like from the power receiving device 6.

The control unit 16 controls each of the power source unit 8 and thewireless communication unit 14. For example, the control unit 16controls the voltage value of the AC power supplied by the power sourceunit 8 based on power receiving information received by the wirelesscommunication unit 14. Note that the control unit 16 has a CPU (CentralProcessing Unit), ROM (Read Only Memory), RAM (Random Access Memory)(none of which are illustrated in the drawings) and the like. Controlprograms for controlling the power feeding device 4 are stored in theROM. The CPU integrally controls the power feeding device 4 by executingthe control programs stored in the ROM. The RAM is used as a temporarystorage region (operation region) for various processes executed in theCPU.

1-3. Configuration of Power Receiving Device

Next, the configuration of the power receiving device 6 according to oneor more embodiments of the present invention will be described referringto FIG. 1.

As illustrated in FIG. 1, the power receiving device 6 has a powerreceiving coil 20, a resonance circuit 22, a rectifier circuit 24, aDC/DC converter 26, a load 28, a detection unit 30, a wirelesscommunication unit 32, and a control unit 34.

The power receiving coil 20 is a so-called secondary coil that generatesAC power by induced electromotive force caused by a flux changegenerated by the power feeding coil 12 of the power feeding device 4.

The resonance circuit 22 resonates at a resonance frequency that issubstantially the same as the resonance frequency of the resonancecircuit 10 of the power feeding device 4.

The rectifier circuit 24 rectifies AC power supplied from the powerreceiving coil 20 via the resonance circuit 22 into DC power. Therectifier circuit 24 is configured by a bridge rectifier circuitincluding, for example, four diodes.

The DC/DC converter 26 steps-up or steps-down the voltage value of DCpower supplied from the rectifier circuit 24 to a prescribed voltagevalue.

The load 28 includes a secondary battery that can be charged anddischarged. The DC power supplied from the DC/DC converter 26 is chargedto the load 28 as a secondary battery. Note that the load 28 may includea load other than a secondary battery that can be charged anddischarged.

The detection unit 30 detects the voltage value of the DC powerrectified by the rectifier circuit 24, and outputs power receivinginformation, which is information relating to the detected voltagevalue, to the control unit 34.

The wireless communication unit 32 carries out wireless communicationwith the power feeding device 4 based on, for example, the BLE method.The wireless communication unit 32 transmits, for example, powerreceiving information and the like output from the control unit 34 tothe power feeding device 4.

The control unit 34 controls each of the DC/DC converter 26 and thewireless communication unit 32. For example, the control unit 34instructs the wireless communication unit 32 to transmit power receivinginformation from the detection unit 30 to the power feeding device 4.Note that the control unit 34 has a CPU, ROM, RAM, and the like (none ofwhich are illustrated in the drawings). Control programs for controllingthe power receiving device 6 are stored in the ROM. The CPU integrallycontrols the power receiving device 6 by executing the control programsstored in the ROM. The RAM is used as a temporary storage region forvarious processes executed in the CPU.

1-4. Operation of the Power Feeding Device

Next, the operation of the power feeding device 4 according to one ormore embodiments of the present invention (power feeding method) will bedescribed referring to FIG. 2 to FIG. 4B. FIG. 2 is a flowchartillustrating the flow of operations of the power feeding device 4according to one or more embodiments of the present invention. FIG. 3 isa time chart illustrating a short beacon and a long beacon transmittedfrom the power feeding device 4 according to one or more embodiments ofthe present invention. FIGS. 4A-4B are schematic diagrams for describingthe operation of the power feeding device 4 according to one or moreembodiments of the present invention.

As illustrated in FIG. 2, first, when 250 ms passes from when theoperation of the power feeding device 4 begins (YES in S1), the wirelesscommunication device 14 of the power feeding device 4 beginstransmission of a short beacon to confirm whether the power receivingdevice 6 is installed on or set in a power feeding space of the powerfeeding device 4 (S2). Here, as illustrated in FIG. 3, the short beaconis a power signal for a short period of time (for example, 30 ms) havinglow power, and is transmitted in cycles of, for example, 250 ms.

While the short beacon is being transmitted, the generation of loadfluctuation in the power feeding device 4 is detected to confirm whetherthe power receiving device 6 is installed on the power feeding device 4.When the power receiving device 6 is not installed on the power feedingdevice 4, the generation of load fluctuation is not detected in thepower feeding device 4 (NO in S3). In this case, when 30 ms passes fromwhen the transmission of the short beacon begins (YES in S4), thewireless communication unit 14 of the power feeding device 4 stops orsuspends the transmission of the short beacon (S5). After this, when 250ms passes from when the transmission of the short beacon stops (YES inS1), step S2 is executed in the same manner as described above.

It is returned to step S3, and when the power receiving device 6 (or aforeign material other than the power receiving device 6) is installedon the power feeding device 4, the generation of load fluctuation isdetected in the power feeding device 4 (YES in S3). In this case, asillustrated in FIG. 3, the wireless communication unit 14 of the powerfeeding device 4 switches from transmission of the short beacon totransmission of the long beacon (S6). Here, as illustrated in FIG. 3,the long beacon is a power signal for a long period of time sufficientfor starting the power receiving device 6 (for example, 105 ms) havinghigh power.

After this, the control unit 16 of the power feeding device 4 formats(deletes) advertise information stored in the memory (not illustrated inthe drawings), and resets number information of the power receivingdevice 6 stored in the memory to “0” (S7). Note that advertiseinformation is information included in an advertise signal (one exampleof a signal) transmitted from the power receiving device 6, andincludes, for example, a Bluetooth (registered trademark) device address(one example of an address), an identification (ID), and a receivedsignal strength indicator (RSSI), and the like. Furthermore, the numberinformation of the power receiving device 6 is information relating tothe number of power receiving devices 6 to which the advertise signalhas been transmitted. For example, when the number information of thepower receiving device 6 is “2”, this means that advertise signals aretransmitted having two different signal receiving devices.

In step S8, when a foreign material other than the power receivingdevice 6 is installed on the power feeding device 4, the wirelesscommunication unit 14 of the power feeding device 4 does not receive anadvertise signal (NO in S8). In this case, when 105 ms passes from whenthe transmission of the long beacon starts (YES in S9), the wirelesscommunication unit 14 of the power feeding device 4 stops thetransmission of the long beacon (S10). After this, it is returned tostep S1 described above.

Returning to step S8, when the power receiving device 6 is installed onthe power feeding device 4, the power receiving device 6 is started bythe long beacon being received. By this, the wireless communication unit32 of the power receiving device 6 broadcast transmits an advertisesignal. When the wireless communication unit 14 of the power receivingdevice 4 receives an advertise signal (YES in S8), the control unit 16of the power feeding device 4 stores advertise information included inthe advertise signal to the memory, and the number information of thepower receiving device 6 stored in the memory is incremented from “0” to“1” (S11).

Here, in step S12, as illustrated in FIG. 4A, a case will be describedwherein there is no other power feeding device around the power feedingdevice 4.

Until a predetermined period of time passes (for example, 150 ms) fromwhen the first advertise signal is received in step S8, the wirelesscommunication unit 14 of the power feeding device 4 waits to receiveanother advertise signal. When a predetermined period of time passesfrom when the first advertise signal is received in step S8 (YES in S13)without the wireless communication unit 14 of the power feeding device 4receiving another advertise signal (NO in S12), the number informationof the power receiving device 6 is set at “1” (YES in S14).

In this case, the power feeding device 4 establishes a wirelesscommunication connection with the power receiving device 6, which is thesource of the advertise signal (S15). After this, an exchange and anegotiation of personal data is completed between the power feedingdevice 4 and the power receiving device 6. After this, the control unit16 of the power feeding device 4 begins power feeding control of thepower source unit 8 based on the power receiving information from thepower receiving device 6 (S16). Note that, as in FIG. 3, the wirelesscommunication unit 32 of the power receiving device 6 transmits powerreceiving information to the power feeding device 4 in cycles of, forexample, 250 ms.

Returning to step S12, as illustrated in FIG. 4B, a case will bedescribed wherein there is another power feeding device 4′ around thepower feeding device 4. In the example illustrated in FIG. 4B, the twopower feeding devices 4 and 4′ are arranged in a line, and two powerreceiving devices 6 and 6′ are installed almost at the same time on thetwo power feeding devices 4 and 4′. At this time, the operationsdescribed above are performed in each of the two power feeding devices 4and 4′.

In this case, the wireless communication unit 14 of the power feedingdevice 4 not only receives an advertise signal from the power receivingdevice 6, which is its pair, but also an advertise signal from the powerreceiving device 6′, which is the pair of the other power feeding device4′ (YES in S12). After this, the control unit 16 of the power feedingdevice 4 stores advertise information included in the advertise signalfrom the power receiving device 6′ to the memory, and increments thenumber information of the power receiving device 6 stored in the memoryfrom “1” to “2” (S17).

Until a predetermined period of time passes from when the firstadvertise signal is received in step S8 (NO in S13), the determinationin step S12 described above is repeatedly executed. When a predeterminedperiod of time has passed from the receiving of the first advertisesignal in step S8 (YES in S13), the number information of the powerreceiving device 6 stored in the memory is set at “2” (NO in S14).

After this, the control unit 16 of the power feeding device 4 sets apower feeding stopping period (one example of a predetermined period oftime), which is a period of time in which the feeding of power (in otherwords, the transmission of the long beacon) to the power receivingdevice 6 is stopped (S18). For example, the control unit 16 of the powerfeeding device 4 generates a random number based on a Bluetooth(registered trademark) device address (6-byte numeral) assigned to thepower feeding device 4. Then, the control unit 16 sets the power feedingstopping period based on this random number (for example, 100 ms).Because this random number is a number specific to the power feedingdevice 4, the set power feeding stopping period also becomes a timespecific to the power feeding device 4. In other words, the powerfeeding stopping period set by the power feeding device 4 (for example,100 ms) and the power feeding stopping period set by the power feedingdevice 4′ (for example, 200 ms) are different times.

After this, the control unit 16 of the power feeding device 4 stopsfeeding power to the power receiving device 6 by controlling the powersource unit 8 (S19). By this, the transmission of the advertise signalfrom the power receiving device 6, which is the pair of the powerfeeding device 4, stops. Similarly, because the feeding of power fromthe power feeding device 4′ to the power receiving device 6′ stops, thetransmission of the advertise signal from the power receiving device 6′,which is the pair of the power feeding device 4′.

When the power feeding stopping period passes after the feeding of powerto the power receiving device 6 has stopped (YES in S20), the wirelesscommunication device 14 of the power feeding device 4 begins feedingpower to the power receiving device 6 (in other words, transmission ofthe long beacon) again (S6). In this case, steps S6 to S8 are executedin the same manner as described above. At this time, because the feedingof power to the power receiving device 6′ begins once again in the powerfeeding device 4′ after the power feeding device 4, the power receivingdevice 6′ still does not start. By this, because the power receivingdevice 6′ does not transmit an advertise signal, the wirelesscommunication unit 14 of the power feeding device 4 only receives anadvertise signal from the power receiving device 6, which is its pair(YES in S8).

After this, the control unit 16 of the power feeding device 4 storesadvertise information included in the advertise signal to the memory,and increments the number information of the power receiving device 6stored in the memory from “0” to “1” (S11).

Until a predetermined period of time passes from when the firstadvertise signal is received in step S8, the number information of thepower receiving device 6 stored in the memory is set to “1” (YES in S14)when the power receiving device 6′ still has not started (in other wordswhen the power feeding stopping period set by the power feeding device4′ has not yet passed) (NO in S12, YES in S13).

In this case, the power feeding device 4 can establish a wirelesscommunication connection with the power receiving device 6, which is itspair (S15). Afterward, step S16 is executed as described above.

After this, when the power receiving device 6′ starts after the powerfeeding stopping period set by the power feeding device 4′ passes, thesame operations as described above are also carried out in the powerfeeding device 4′. By this, the power feeding device 4′ can alsoestablish a wireless communication connection in a similar manner withthe power receiving device 6′, which is its pair.

1-5. Effects

Next, effects achieved by the power feeding device 4 according to one ormore embodiments of the present invention will be described. Asdescribed above, when, for example, two power feeding devices 4 and 4′are arranged in a line, the wireless communication unit 14 of the powerfeeding device 4 not only receives an advertise signal from the powerreceiving device 6, which is its pair (in other words, power is fed bythe power feeding device 4), but also an advertise signal from the powerreceiving device 6′, which is not its pair (in other words, power is notfed by the power feeding device 4).

In this case, the control unit 16 of the power feeding device 4 sets apower feeding stopping period which is a time specific to the powerfeeding device 4, and the feeding of power to the power receiving device6 is stopped during the set power feeding stopping period. By this, thetiming of starting to feed power again to the power receiving device 6and the timing of starting to feed power again to the power receivingdevice 6′ is different. As a result, because the power feeding device 4only receives an advertise signal from the power receiving device 6,which is its pair, wireless communication with the power receivingdevice 6, which is its pair, can be correctly carried out, and theoccurrence of a so-called cross-connection can be suppressed.

Therefore, the power feeding device 4 can reliably receive powerreceiving information from the power receiving device 6, which is itspair, and the feeding of power to the power receiving device 6 can bereliably carried out based on this power receiving information.

Next, a power feeding device 4A according to one or more embodiments ofthe present invention will be described referring to FIG. 5 and FIG. 6.FIG. 5 is a schematic diagram for describing the operation of the powerfeeding device 4A according to one or more embodiments of the presentinvention. FIG. 6 is a flow chart illustrating the flow of operations ofthe power feeding device 4A according to one or more embodiments of thepresent invention. Note that FIG. 1 should be appropriately referencedin regards to the reference symbols for each component in the powerfeeding device 4A and the power receiving devices 6 a and 6 b. Also, inthe flowchart of FIG. 6, the same step numbers are given for the stepsof the same processes in the flowchart of FIG. 2.

As illustrated in FIG. 5, a plurality of a power receiving device (forexample, two devices) 6 a and 6 b can be installed on the power feedingdevice 4A according to one or more embodiments of the present invention.The power feeding device 4A can wirelessly feed power to each of theplurality of the installed power receiving device 6 a and 6 b at thesame time.

The operation of the power feeding device 4A according to one or moreembodiments of the present invention will be described referring to FIG.6. First, the control unit 16 of the power feeding device 4A formatsadvertise information stored in the memory, and resets a retry countstored in the memory to “0” (S31). Note that the retry count isinformation indicating the number of times the stopping and restarting(the suspending and resuming) of power feeding is repeated to the powerreceiving devices 6 a and 6 b as described later.

A case will be described here wherein only one of the power receivingdevice 6 a (or the power receiving device 6 b) is installed on the powerfeeding device 4A. In this case, steps S1 to S16 are executed in thesame manner as the aforementioned embodiments after step S31. Note thatin step S7 a, the control unit 16 of the power feeding device 4 isdifferent than in step S7 of FIG. 2 described in the aforementionedembodiments in that it only carries out a process for resetting thenumber information of the power receiving device 6 stored in the memoryto “0”, and does not format advertise information stored in the memory.

Below, a case will be described wherein a plurality of the powerreceiving device 6 a and 6 b is installed on the power receiving device4A. In this case, steps S1 to S14, and step S17 are executed in the samemanner as the aforementioned embodiments after step S31. In step S14,the number information of the power receiving device 6 stored in thememory is set at “2” (NO in S14).

After this, the control unit 16 of the power feeding device 4Adetermines that two sets of advertise information are newly stored tothe memory in each of steps S11 and S17 of this loop (NO in S32), andthe retry count stored in the memory is held at “0” (S33).

After this, the control unit 16 of the power feeding device 4A sets thepower feeding stopping period in the same manner as the aforementionedembodiments (S18) and stops feeding power to the power receiving devices6 a and 6 b by controlling the power source unit 8 (S19). When the powerfeeding stopping period passes after the feeding of power to the powerreceiving devices 6 a and 6 b has stopped (YES in S20), the wirelesscommunication device 14 of the power feeding device 4A once again beginsfeeding power to the power receiving devices 6 a and 6 b (in otherwords, transmission of the long beacon) (S6). After this, steps S7 toS14 are executed as described above.

After this, the control unit 16 of the power feeding device 4Adetermines whether the two sets of advertise information stored in thememory in each of steps S11 and S17 in this loop are the same as the twosets of advertise information stored in the memory each of steps S11 andS17 of the previous loop (S32). When the control unit 16 of the powerfeeding device 4A determines that they are the same (YES in S32), theretry count stored in the memory is incremented from “0” to “1” (S34).

When the retry count stored in the memory is not exceeding a prescribedvalue (for example, “3”) (NO in S35), steps S18 to S20 and each stepfrom S6 onward are executed as described above. In other words, theretry count stored in the memory increments only by “1” each time thestopping and restarting of the feeding of power to the power receivingdevices 6 a and 6 b is repeated once. As described above, the stoppingand restarting of the feeding of power to the power receiving devices 6a and 6 b is repeated until the retry count stored in the memory exceedsa prescribed amount.

When the retry count stored in the memory exceeds a prescribed amount(YES in S35), the control unit 16 of the power feeding device 4Adetermines that the wireless communication unit 14 has received two ofthe same advertise signals each time the stopping and restarting of thefeeding of power is repeated a plurality of times, and determines thatthe power receiving device 6 a and 6 b, which are the source of the twoadvertise signals, are all installed on the power feeding device 4A. Inthis case, the power feeding device 4A establishes a wirelesscommunication connection with the power receiving devices 6 a and 6 b,which are the source of the two advertise signals (S36). After this, thecontrol unit 16 of the power feeding device 4A begins power feedingcontrol of the power source unit 8 based on the power receivinginformation from the power receiving units 6 a and 6 b (S16). Note thatthe control unit 16 of the power feeding device 4A sets power feedingconditions (for example, voltage value and the like) to carry out thefeeding of power to each of the power receiving devices 6 a and 6 bbased on the two advertise signals received by the wirelesscommunication unit 14.

As described above, in one or more embodiments of the present invention,the control unit 16 of the power feeding device 4A determines that thewireless communication unit 14 has received two of the same advertisesignals each time the stopping and restarting of the feeding of power isrepeated a plurality of times, and determines that the plurality of thepower receiving device 6 a and 6 b are all installed on the powerfeeding device 4A. By this, for example, the other power receivingdevice can be suppressed from determining in error that they areinstalled in the power feeding devices 4A based on the advertise signalfrom the other power receiving device (not illustrated in the drawings)installed on the other power feeding device (not illustrated in thedrawings) other than the power feeding device 4A.

Next, a power feeding device 4B according to one or more embodiments ofthe present invention will be described referring to FIG. 7 and FIG. 8.FIG. 7 is a schematic diagram for describing the operation of the powerfeeding device 4B according to one or more embodiments of the presentinvention. FIG. 8 is a flow chart illustrating the flow of operations ofthe power feeding device 4B according to one or more embodiments of thepresent invention. Note that FIG. 1 should be appropriately referencedin regards to the reference symbols for each component in the powerfeeding devices 4B and 4B′ and the power receiving devices 6 and 6′.Furthermore, in the flowchart of FIG. 8, the same step numbers are givenfor the steps of the same processes in the flowchart of FIG. 2.

As illustrated in FIG. 7, in one or more embodiments of the presentinvention, two power feeding devices 4B and 4B′ are arranged in a line,and two power receiving devices 6 and 6′ are installed almost at thesame time on each of the two power feeding devices 4B and 4B′.Furthermore, a management unit 36 is disposed, which is a host computerfor managing the two power feeding devices 4B and 4B′. The managementunit 36 and each of the two power feeding devices 4B and 4B′ can, forexample, communicate via wire.

The power feeding device 4B according to one or more embodiments of thepresent invention will be described referring to FIG. 8. When there isno power feeding device 4B′, steps S1 to S16 are executed in a similarmanner to the aforementioned embodiments.

Meanwhile, when two power feeding devices 4B and 4B′ are arranged in aline, steps S1 to S14 and S17 are executed in a similar manner to theaforementioned embodiments. In step S14, the number information of thepower receiving device 6 stored in the memory is set at “2” (NO in S14).

After this, the control unit 16 of the power feeding device 4A stops thefeeding of power to the power receiving device 6 by controlling thepower source unit 8 (S19). After this, the wireless communication unit14 of the power feeding device 4B transmits a confirmation requestsignal to the management device 36 (S41). The management device 36confirms whether a confirmation request signal has been transmitted fromthe other power feeding device 4B′ when it receives the confirmationrequest signal from the power feeding device 4B. In one or moreembodiments of the present invention, the power feeding device 4B′ alsotransmits a confirmation request signal to the management device 36.

After this, the management device 36 assigns a difference power feedingstopping period to each of the power feeding devices 4B and 4B′ thathave transmitted a confirmation request signal. After this, themanagement device 36 transmits (notifies) a different power feedingstopping period to each of the power feeding devices 4B and 4B′, and thewireless communication unit 14 of each power feeding device 4B and 4B′receives the power feeding stopping period from the management device 36(YES in S42). By this, the power feeding devices 4B and 4B′ stop thefeeding of power to the power receiving devices 6 and 6′ only for theassigned power feeding stopping period (S20).

As described above, in one or more embodiments of the invention, becausethe management device 36 sets a power feeding stopping period, theconfiguration of the control unit 16 can be simplified more than in theaforementioned embodiments in which the control unit 16 sets the powerfeeding stopping period.

(Variations)

The power feeding devices and power feeding methods according to one ormore embodiments of the present invention were described above, but thepresent invention is not limited to those embodiments. For example, theaforementioned embodiments may each be combined.

In each of the above embodiments, the wireless communication unit 14 ofthe power feeding device 4 (4A, 4B) carries out wireless communicationby Bluetooth (registered trademark), but it is not limited to this, andmay carry out wireless communication by, for example, Wi-Fi (registeredtrademark), NFC (near field communication), or the like.

In each of the above embodiments, the advertise signals included aBluetooth (registered trademark) device address, ID, and a receivedsignal strength indicator, but they may include at least one of these.

(Other Variations)

Furthermore, each of the devices described above may be configured as acomputer system configured by a microprocessor, a ROM (Read OnlyMemory), RAM (Random Access Memory), a hard disk drive, a display unit,a keyboard, a mouse, and the like. Computer programs are stored on theRAM or hard disk drive. Each device achieves its function by themicroprocessor operating in accordance with a computer program. Acomputer program here is configured by a plurality of command codesindicating instructions for the computer, to achieve a prescribedfunction.

Additionally, one or all components that configure each device describedabove may be configured by one system LSI (Large System Integration). Asystem LSI is a multi-functioning LSI manufactured by layering aplurality of components on one chip, and is a computer system configuredincluding a microprocessor, a ROM, a RAM, and the like. Computerprograms are stored on the RAM. The system LSI achieves its function bythe microprocessor operating in accordance with a computer program.

Additionally, one or all components that configure each device may beconfigured by an IC card or a simple module that can be attached andremoved from each device. An IC card or module is a computer systemconfigured by a microprocessor, a ROM, a RAM, and the like. The IC cardor module may include the multi-functioning LSI described above. The ICcard or module achieves its function by the microprocessor operating inaccordance with a computer program. This IC card or module may be tamperresistant.

Furthermore, one or more embodiments of the present invention may be amethod shown above. Furthermore, one or more embodiments of the presentinvention may be a computer program for realizing this method using acomputer, and may be a digital signal made up of a computer program.

Additionally, one or more embodiments of the present invention mayrecord the computer program or digital signal described above onto anon-temporary recording medium such as, for example, a flexible disk, ahard disk, a CD-ROM, an MO, a DVD, a DVD-ROM, a DVD-RAM, a BD (Blu-ray(registered trademark) Disc), or a semiconductor memory. Furthermore, itmay be the digital signal described above recorded on a non-temporaryrecording medium.

Furthermore, one or more embodiments of the present invention maytransmit the computer program or digital signal described above viaelectric communication lines, wireless or wired communication lines, anetwork represented by the internet, data broadcasting, or the like.

Moreover, one or more embodiments of the present invention may be acomputer system provided with a microprocessor and a memory, wherein thememory stores the computer program described above and themicroprocessor operates following the computer program described above.

Moreover, it may be carried out by another independent computer systemby recording and transferring the program or digital signal describedabove to the non-temporary recording medium, or by transferring theprogram or digital signal described above via the network or the like.

Although the disclosure has been described with respect to only alimited number of embodiments, those skilled in the art, having benefitof this disclosure, will appreciate that various other embodiments maybe devised without departing from the scope of the present invention.Accordingly, the scope of the invention should be limited only by theattached claims.

The power feeding device of one or more embodiments of the presentinvention can be used as, for example, a power feeding platform thatfeeds power wirelessly to an electronic apparatus such as a smartphone.

DESCRIPTION OF THE REFERENCE SYMBOLS

-   2 Wireless power feeding system-   4, 4′, 4A, 4B, 4B′ Power feeding device-   6, 6′, 6 a, 6 b Power receiving device-   8 Power source unit-   10, 22 Resonance circuit-   12 Power feeding coil-   14, 32 Wireless communication unit-   16, 34 Control unit-   18 Commercial power source-   20 Power receiving coil-   24 Rectifier circuit-   26 DC/DC converter-   28 Load-   30 Detection unit-   36 Management device

What is claimed is:
 1. A power feeding device, comprising: a powerfeeder that wirelessly feeds power to one of a plurality of powerreceivers, a transceiver that communicates with the plurality of powerreceivers, and a controller that, when the transceiver receives aplurality of signals from two or more of the plurality of powerreceivers, causes the power feeder to suspend the feeding of power tothe one of the plurality of power receivers for a predetermined period.2. The power feeding device according to claim 1, wherein the controllersets the predetermined period that is different from anotherpredetermined period set for another power feeding device.
 3. The powerfeeding device according to claim 2, wherein the controller sets thepredetermined period based on a random number specific to the powerfeeding device.
 4. The power feeding device according to claim 3,wherein the controller generates the random number based on an addressassigned to the power feeding device.
 5. The power feeding deviceaccording to claim 1, wherein each of the plurality of signals includesat least one of an address, an ID, and a received signal strengthindicator of the power receiver.
 6. The power feeding device accordingto claim 1, wherein the controller controls the power feeder based on asignal received when causing the power feeder to resume the feeding ofpower.
 7. The power feeding devices according to claim 1, wherein thepower feeder wirelessly feeds power to each of the plurality of powerreceivers, and wherein the controller: repeats suspending of the powerfeeding a plurality of times when the transceiver receives the pluralityof signals from the plurality of power receivers; and determines thatthe plurality of power receivers exists in a power feeding space of thepower feeding device when the transceiver continues to receive samesignals from each of the plurality of power receivers.
 8. The powerfeeding device according to claim 7, wherein the controller sets powerfeeding conditions for the power feeder to feed power to each of theplurality of power receivers based on the signals received from theplurality of power receivers.
 9. The power feeding device according toclaim 1, wherein the transceiver communicates with a management devicethat manages the power feeding device and notifies the power feedingdevice of the predetermined period via the transceiver.
 10. The powerfeeding device according to claim 1, wherein the transceiver transmits afirst beacon signal, and each of the plurality of signals is transmittedresponding to the beacon signal.
 11. The power feeding device accordingto claim 10, wherein when load fluctuation is detected, the transceivertransmits a second beacon signal having higher power than the firstbeacon signal.
 12. The power feeding device according to claim 1,wherein the plurality of signals are advertisement signals.
 13. Thepower feeding device according to claim 12, wherein the controllercounts a total number of the plurality of power receivers based on theadvertisement signals.
 14. The power feeding device according to claim13, wherein the advertisement signals are transmitted according to aBluetooth standard.
 15. A power feeding method performed by a powerfeeding device, comprising: wirelessly feeding power to one of aplurality of power receivers, communicating with the plurality of powerreceivers, and when a plurality of signals are received from two or moreof the plurality of power receivers, suspending the feeding of power tothe one of the plurality of power receivers for a predetermined period.16. The power feeding method according to claim 15, further comprisingsetting the predetermined period that is different from anotherpredetermined period set for another power feeding device.
 17. The powerfeeding method according to claim 16, wherein the predetermined periodis set based on a random number specific to the power feeding device.18. The power feeding method according to claim 17, further comprisinggenerating the random number based on an address assigned to the powerfeeding device.
 19. The power feeding method according to claim 15,wherein each of the plurality of signals includes at least one of anaddress, an ID, and a received signal strength indicator of the powerreceiver.
 20. The power feeding method according to claim 15, whereinthe power feeder is controlled based on a signal when resuming thefeeding of power.